Ultrasound examination of the gonads of the african clary catfish in industrial aquaculture

Abstract

The article is devoted to ultrasound examination of the gonads of the African clary catfish. Data on the state of the reproductive system of fish are the basis for the formation of a high-quality breeding stock. In mature fish, the state of the gonads is an informative indicator and reflects the general physiological state of the body. The object of the study was the African clarias catfish (Clarias gariepinus). A group of 10 individuals, including 5 males and 5 females, was selected for the work. The gonads were examined using the Mindray DP-50 ultrasound machine. A linear ultrasonic sensor was used to assess the gonads of the African clary catfish. The study was conducted in winter 2023. The aim of the work was an ultrasound assessment of the condition, the stage of maturity of the gonads and their variability in females and males of the African clary catfish. A study of the gonads of females, which by age and weight belong to the category of sexually mature, revealed in them the signs inherent in the gonads of the IV stage of maturity. This is typical for fish in aquaculture conditions. Ultrasound diagnostics showed that the gonads of the IV completed stage of maturity, in the upper part isoechoic, are filled with hyperechoic inclusions of high density in the form of oocytes. In the lower medial part there are hypoechoic areas with low density along the entire length of the gonads. The results of ultrasound examination of the testicles of male clary catfish showed that they are of the IV stage of maturity, enclosed in a hyperechoic shell along the entire length. Both testes have a uniform hyperechogenic fine-grained structure of high density. The lobes of both testes are not the same, clearly visualized, increased density. The results of the research allow us to conclude that ultrasound diagnostics of the sex and the study of the gonads of fish can be carried out on an ongoing basis, as it is not only painless, but also a highly informative procedure. For fish species that have lost their ability to reproduce in aquaculture conditions, determining the maturity stage of gonads using ultrasound will allow for scientifically sound hormonal stimulation and fertilization.